1. Technical Field
The present disclosure relates to sensors, and in particular, relates to a method for fabricating carbon nanotube array sensor.
2. Description of the Related Art
Carbon nanotubes can function as either a conductor, like metal, or a semiconductor, according to the rolled shape and the diameter of the helical tubes. With metallic-like nanotubes, it has been found that a one-dimensional carbon-based structure can conduct a current at room temperature with essentially no resistance. Further, electrons can be considered as moving freely through the structure, so that metallic-like nanotubes can be used as ideal interconnects. When semiconductor nanotubes are connected to two metal electrodes, the structure can function as a field effect transistor, wherein the nanotubes can be switched from a conducting to an insulating state by applying a voltage to a gate electrode. Therefore, carbon nanotubes are potential building blocks for nanoelectronic devices because of their unique structural, physical, and chemical properties.
Carbon nanotubes have been shown to be a highly sensitive chemical and biological sensor. The utility of detecting the presence or absence of a specific agent is one type of known detection scheme. As the agent attaches itself to a carbon nanotube, the measurable resistance of the nanotube changes. As the resistance changes, a quantitative result, e.g., concentration may be determined. Known nanotube systems use a single nanotube (only one path for determining resistance), a parallel array of nanotubes, or a network array of nanotubes to determine the presence of an unwanted agent. A conventional carbon nanotube array sensor includes a carbon nanotube array and two electrodes respectively disposed opposite ends of the carbon nanotube array along a longitudinal axis thereof. In a method of making the carbon nanotube array sensor, the carbon nanotube array is directly adhered on surfaces of the two electrodes via gold slurry.
However, the gold slurry is conductive material and includes insulative solvent and binder besides gold particles. Therefore, conductive capacity between the carbon nanotube array and the two electrodes can be decreased. Furthermore, the carbon nanotube array has no firm connection to the two electrodes because of bad wettability between the gold slurry and the carbon nanotube array, thereby decreasing sensitivity and precision of the carbon nanotube array sensor.
What is needed, therefore, is a carbon nanotube array sensor and a method for fabricating the same, which can overcome the above-described shortcomings.